Process of extracting neutral grease from wool scouring water and treating same



April 12, M PROCESS OF EXTRACTING NEUTRAL GREASE FROM WOOL SCOURING WATER AND TREATING SAME Filed March 8, 1929 Invent 0r; Eugne Mertens Attorney.-

' m ing process.

rammed Apr. 12, 1932 UNITED- STATES PATENT oFFzcE EUGENE MEBTENS, or LouvAm. BELGIUM PROCESS or ax'rnac'rme norm GREASE rnom woor. scouanwe warm; AND

' 'rnm'rme sum Application filed ltarch 8, 1929, Serial No. 345:553, and in Belgium November 6,1928.

My present invention has for its object to provide an improved process of extracting neutral grease contained in Wl scouring water and subsequently treating same for ob-' taining grease designed for pharmaceutical and industrial purposes.

' The water used for scouring wool containsup to 23% of neutral grease according to the nature of the wool treated and the scour- The neutral grease of the wool is distributed in the scouring water in the state of fine par.- ticles in presence of soap, potash, mineral impurities, albumenoids and other organic impurities.

The problem to be solved consists in removing such grease without too many impurities and then purifying same to remove soap, mineral and organic impurities, particularly albumenoids therefrom, so as to obtain perfectly neutral, unalterable grease which does not grow rancid and is scentless and of light yellow colour. v

Heretofore in many cases sulphuric acid has been used for obtaining such neutral grease from wool. The. scouring water has been treated wit sulphuric acid to separate the whole of the} atty materials, fatty acids an and neutral grease from the water and impurities. ()r the fat and. grease was first concentrated in the scum obtained upon mechanically churning the water and such scum was treated with sulphuric acid. Fatty materials were then separated by filtration and a mixture of fatty acids from soap and neutral grease from yelk has been obtained. The neutral grease was extracted from such mixture by means of various processes which are 0 imperfect and expensive and by which it is adulterated and loses the major part of its value. It has also been suggested to extract neutral grease from scouring water by means of purely mechanical processes without the use of reagents. By mixing air with the water to be treated and throwing such mixture against a partition, the substances in suspension, colloidal substances and particles. of

- neutral grease will be agglutinatedand may beseparated from water. Such processes are objectionable in-that they are very expensive and produce very impure rough grease which .is not easily treated by the usual refining processes.

. Some processes have also been proposed which cause flotation of the fatty substances 5 according to the known process of froth flotation by means of finely divided bubbles of an and then stabilizing the floated particles by washing out the film of liquor covering them, and, by this means, causing the parti cles to adhere together, especially when they have cooled and hardened. These processes are objectionable in that they arevery ex ensive owing to the quantity and pressure 0 air required to float the fatty substances, and

their operation is most diflicult owing to the necessity of dealing with the liquor at certain exact conditions of temperature.

The process of recovering neutral grease according to this invention consists in the go combinationv of the following steps carried out successively.

As above stated, the neutral grease of the wool is distributed in the scouring water as fine particles. These will not separate from 7 the water because of their minuteness, for their adherence to the water is equal to or greater than their tendency to rise owing-to the difference in the specific gravity between them and the water. ,The first step of this so invention consists in heating or churning the wool scouring water, preferably when it is cold, and thereby causing the fine particles of grease to be thrown against each other and to agglutinate into larger'particles which 83' separate from the water, their adherance to the liquor being less than their buoyancy due to their lesser specific gravity as compared with the liquor. The larger particles of grease thus formed rise to the surface of the liquor, also, especially during the beating of the water, the emulsifying agents, such as soap, from a very light foam which helps the particles of grease to rise, and consequently facilitates their removal.

The second step of this invention is the washing of such foam to remove the soap and other soluble substances and to precip1- tate a part of the albuminoids, mineral impurities, and other heavy substances. This 1 g containing soap and other soluble substances in solution into a collecting tank where the grease rises to the surface of the water and is removed for further treatment while the water is disposed of as may be found useful.

1 The grease as recovered appears in the form driving the churning apparatus of an emulsified scum which contains about .7 5% water, 20% neutral grease and 5% soap, albuminoids and mineral impurities This emulsified scum does not melt whenheated, but s'wells and rises like milk. The third step of this invention consists in treating this product in a digester under a pressure of two to three atmospheres and an adequate temperature of 90 to 120 degrees centigrade. Inthe digester, the emulsion is-destroyed due to the fact that the product cannot swell because of the pressure, and the albuminoids coagulate andsink to the bottom "together with the heavy impurities.

.The grease recovered trom the digester is practically anhydrous and scentless, and may. be-used for many purposes. It may be easily refined by the usual processes for removing remaining impurities. v The improved process is particularly simple and does not require complicated devices, low motive power being sufiicient for The washing of the scum requires a small amount of water only if good atomizers are used. The treatment in the digester, which may be effected continuously or not, requires very few calories only. a

Having thus xplained 'thewrinciples of this invention, itcwill now be described, by way of example, in connection with a sche matic illustration. 1

In the accompanying sheet of drawings which forms apart of this description, Figure 1 is an elevation of an apparatus churning apparatus with four pairsjof padd1e wheels, a washing channel and a collecting tank with a constant head of water. Fig. 2 is a plan view of the same, and Fig; .3 is a vertical section on the line III-III of Figs. 1 and 2.

The apparatus comprises parallel channels 0,, C2, C8 and C arranged side by side. These channels are slightly inclined so that water fed into the first channel from the pipe A flows down along the channels and is constantly discarded through a discharge pipe 'K. Across the channels are provided four pairs of paddle wheels mounted on two axles.

' Fig. 1 shows such paddle wheels R and R These turn in opposite directions as indicated by the arrows. When passing under the paddle wheels, the water is beaten or for carrying out this invention which includes a and other emulsifying agents, and this scum helps surface. The scum and the particles of grease collect in the channels between the two lines of paddle wheels. Here the sides extend only an inch or'two above the level of 'the water. The outer wall W of the first channel C is at a certain level and the successi've inner wallsW W W and the outer wall W; are at progressively lower levels.

-The scum containing grease in. suspension produced" inthetrough C collects in the space between the paddle wheels and accumulates on top'of the water. When this scum rises above the top of the wall W it spills over this wall into the channel C Likewise the scum accumulates in the channels C C and C and overflows from each into the next and finally over the wall W into the washing channel D; This channel as shown in igs. 2 and 3 is formed. of several sections-D, D and D with a slope. In this channel are provided atomizers P P and P which spra finely divided water uponthescum whic flows in the direction of the arrows; This spraying of the scum dissolves the soap and other soluble substances contained in the scum and washes out mineral impurities and the particles of grease to rise to the I albumenoids. These settle down on the bottom of the channeland collect in the pockets E, E in the floor of the channel and are withdrawn therefrom as the pockets become filled. The scum and water flow to the tank B. The particles of grease collect at the surface of the water and the water with soap and other soluble substances are extracted by a lmown device which maintains a constant level of water in the tank.

Theemulsion of grease is then treated in a digester under a pressureof two to three atmospheres and at 'a temperature of 90 to 120 degrees centigrade as explained.

Having now fully described my said invention, what I claiin and desire-to secure by Letters Patent, is: l

The process of extracting neutral grease from wool scouring water and treating the same, which consists in churning the wool scouring water for the purpose of producing scum containing neutral grease particles,

Eheres for separating neutral, practically an- 1255 ydrous and scentless grease.

EUGENE MERTENS.

churned, and thereby the particles which 

